Portable instrument and docking station with divided universal serial bus communication device

ABSTRACT

A universal serial bus (USB) communication system includes a portable instrument and a docking station that communicate with a host device using a divided USB communication device. A first portion of the USB communication device is provided in the portable instrument. A second portion of the USB communication device is provided in the docking station. The first portion includes a non-USB communication device that communicates with the second portion in a non-USB format. The second portion converts the communications into a USB format suitable for the host device.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.13/740,455 filed on Jan. 14, 2013, issued on May 3, 2016 as U.S. Pat.No. 9,330,046, and entitled PORTABLE INSTRUMENT AND DOCKING STATION WITHDIVIDED UNIVERSAL SERIAL BUS COMMUNICATION DEVICE, the disclosure ofwhich is hereby incorporated by reference in its entirety.

BACKGROUND

Various techniques exist for transmitting data between electronicdevices. One common technique is referred to as serial datacommunication. Serial communication typically involves the transmissionof data in a data stream, one bit at a time. The data is typicallytransmitted across a single conductor at a specified baud rate with highand low voltage levels representing bits (“0” or “1”) of the datastream. Some serial communication standards utilize start and stop bitsto signal the beginning and end of each byte (8 bits) of data.

Another common technique is referred to as Universal Serial Bus (USB)data communication. USB is commonly used both to communicate databetween electronic devices and also to supply power from one of thedevices to the other. The USB data communication standards require thetransmission of various messages back and forth between the electronicdevices, and therefore require that such devices have increasedprocessing capabilities than basic serial communication devices. As aresult, an electronic device that utilizes USB data communication may bemore expensive and complex than an electronic device that utilizesserial data communication.

SUMMARY

In general terms, this disclosure is directed to a USB communicationdevice. In one possible configuration and by non-limiting example, theUSB communication device is divided between a first portion arranged ina portable instrument, and a second portion arranged in a dockingstation.

One aspect is a docking station comprising: a housing having areceptacle formed therein, the receptacle sized and configured toreceive and support at least a portion of a portable medical instrumentand including electrical contacts arranged to electrical connect withthe portable medical instrument, wherein the portable medical instrumentincludes a first portion of a USB communication device adapted tocommunicate in a serial data communication format; and a second portionof the USB communication device enclosed in the housing, the secondportion comprising: a serial to USB converter arranged in the housingand electrically connected to the electrical contacts, wherein theserial to USB converter is arranged and configured to convert betweenthe serial data communication format and a USB data communication formatto facilitate communication between the portable medical instrument anda host device; and electronic circuitry that detects the electricalconnection of the portable medical instrument with the electricalcontacts and initiates the communication with the host device afterdetecting the electrical connection.

Another aspect is a portable medical instrument comprising: instrumentelectronics adapted to generate data associated with a physiologicalcharacteristic of an individual; and a first portion of a USBcommunication device, the first portion comprising: a processing device,the processing device programmed to generate messages in accordance witha USB data communication protocol, at least one of the messagesincluding the data; and a serial communication device that receives themessages from the processing device and transmits the messages to adocking station in a non-USB serial data communication format.

A further aspect is a dockable instrument assembly including a divideduniversal serial bus (USB) communication device configured tocommunicate with a USB-enabled host device, the dockable instrumentassembly comprising: a portable instrument comprising: instrumentelectronics operable to generate data to be communicated to the hostdevice, the data being associated with a physiological characteristic ofan individual; and a first portion of the divided USB communicationdevice comprising a serial communication device, wherein the firstportion is arranged and configured to receive the data from theinstrument electronics and transmit the data in a serial format with theserial communication device; and a docking station comprising: areceptacle sized to receive at least a portion of the portableinstrument therein; a second portion of the divided USB communicationdevice, the second portion comprising a serial to USB converter arrangedand configured to: detect when the portable instrument is inserted intothe receptacle; after detecting insertion of the portable instrumentinto the receptacle, initiate communication with the host device; andfacilitate communication between the portable instrument and the hostdevice.

Yet another aspect is a method of communicating with a USB-enabled hostdevice, the method comprising: monitoring for insertion of a portablemedical instrument into a docking station; detecting the insertion ofthe portable medical instrument into the docking station, the portablemedical instrument configured to communicate with the docking stationthrough a non-USB data communication device in a non-USB format; afterdetecting the insertion of the portable medical instrument, initiatingcommunication with the host device to alert the host device to anarrival of the portable medical instrument; and facilitatingcommunication between the portable medical instrument and the hostdevice.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an example USB communication system.

FIG. 2 is a schematic block diagram illustrating another example of theUSB communication system shown in FIG. 1, including a divided USBcommunication device.

FIG. 3 is a schematic illustrating an example of a first portion of thedivided USB communication device, shown in FIG. 1.

FIG. 4 is a schematic block diagram of an example of a second portion ofthe divided USB communication device, shown in FIG. 1.

FIG. 5 is a schematic diagram illustrating an example implementation ofthe second portion of the divided USB communication device, shown inFIG. 4.

FIG. 6 is a schematic block diagram of an example host device of the USBcommunication system shown in FIG. 1.

FIG. 7 is a flow chart illustrating an example method of communicatingwith a USB-enabled host device.

FIG. 8 is a flow chart illustrating an example method of facilitatingcommunication between a portable instrument and a host device.

FIG. 9 is a flow chart illustrating a method of terminatingcommunication with a USB-enabled host device.

DETAILED DESCRIPTION

Various embodiments will be described in detail with reference to thedrawings, wherein like reference numerals represent like parts andassemblies throughout the several views. Reference to variousembodiments does not limit the scope of the claims attached hereto.Additionally, any examples set forth in this specification are notintended to be limiting and merely set forth some of the many possibleembodiments for the appended claims.

As discussed above, the USB data communication standard defines hardwarerequirements (including hardware requirements for cables and connectors)and data communication protocols for communicating data between two ormore electronic devices. In order to conform to the USB datacommunication standards, a USB communication device will typically havemore intelligence (i.e., processing capabilities) than communicationdevices configured to communicate using other data communicationstandards, such as serial communication. Serial communication typicallypermits data to be communicated from one device to another with a simplestream of bits, for example. As a result, the USB data communicationstandards require USB-enabled devices to have at least a minimal levelof intelligence, which can increase the cost, size, and complexity ofsuch devices.

In one example, the present disclosure describes a USB-enabled device inwhich the communication electronics are divided into two or moreportions. A first portion communicates using a serial data communicationdevice according to a serial data communication protocol. The secondportion converts the serial data communication into a form required tocommunicate according to a USB data communication protocol. This permitsthe first portion to have reduced cost and complexity, for example. Thefirst portion is able to communicate with a USB-enabled host deviceusing the second portion.

FIG. 1 is a perspective view of an example USB communication system 100.In this example, the Universal Serial Bus (USB) communication system 100includes a dockable instrument assembly 102, a USB cable 104, and a hostdevice 106. The example dockable instrument assembly 102 includes aportable instrument 110 and a docking station 112. The example portableinstrument 110 includes an instrument 120 and a cradle 122. The dockingstation 112 includes a USB port 132 that receives and connects with aplug of the USB cable 104. The host device 106 also includes a USB port134 that receives and connects with a plug at the other end of the USBcable 104.

The dockable instrument assembly 102 is a device capable ofcommunicating with the USB-enabled host device 106 according to one ormore USB data communication protocols. In this example, the dockableinstrument assembly 102 includes at least two components, including aportable instrument 110 and a docking station 112.

The portable instrument 110 is an electronic device that generates datato be communicated to the host device 106. In some embodiments, theportable instrument 110 is or includes an instrument 120.

In some embodiments, the portable instrument 110 is single deviceenclosed in a single housing. However, in the example shown in FIG. 1,the portable instrument 110 includes two separate parts. Morespecifically, the portable instrument 110 includes an instrument 120 anda cradle 122. Other embodiments of the portable instrument 110 includemore than two parts.

The instrument 120 is a device that generates and stores data, and it isdesired that such data be transferred to the host device 106. An exampleof an instrument 120 is a medical instrument configured to measure ordetect at least one characteristic of a patient. An example of a medicalinstrument is a thermometer. An example of a thermometer is an infraredear thermometer. Other medical instruments are used in otherembodiments. Several additional examples of medical devices include adigital otoscope, a digital opthalmoscope, and a hand held imagingdevice. Other non-medical instruments are used in yet other embodiments.In this example, the portable instrument 110 also includes a cradle 122.The cradle 122 is a handheld storage unit that supports the instrument120 when the instrument is not in use. The cradle 122 also includesadditional storage compartments, in some embodiments, for storingaccessories for use with the instrument 120, such as disposable probecovers. In some embodiments, the cradle 122 includes electrical contactsthat connect with corresponding electrical contacts on the instrument120 when the instrument 120 is placed into the cradle 122. Theelectrical contacts permit data and/or power to be transferred betweenthe cradle 122 and the instrument 120. In other possible embodiments,however, the portable instrument 110 does not include the cradle 122,and the instrument 120 can be docked directly into the docking station112, for example.

The docking station 112 is a support device that temporarily stores theportable instrument 110 when the portable instrument 110 is not beingused by a user. The docking station can be placed on a desk, table,counter top, or other horizontal structure, for example, or can bemounted to a wall or other vertical structure. The docking station 112typically includes a receptacle sized to receive the portable instrument110. In some embodiments, the docking station 112 electrical contactsarranged in the receptacle. The electrical contacts make contact withcorresponding contacts on the portable instrument 110 for charging theportable instrument 110 and/or for data communication. The dockingstation 112 includes a USB port 132 that receives and connects with aplug of the USB cable 104.

The USB cable 104 includes electrical conductors and conforms to the USBstandards for USB data communication cables.

The host device 106 is an electronic device that receives data from theportable instrument 110 utilizing USB data communication. In theillustrated example, the host device 106 is a vital signs monitor. Anexample of a vital signs monitor is the CONNEX vital signs monitoravailable from Welch Allyn, Inc. of Skaneateles Falls, N.Y. Is anotherexample, the host device 106 is a computing device, such as a desktopcomputer, a laptop computer, a mobile computing device (including asmartphone, tablet computer, etc.), or other device including aprocessor and computer readable storage media, wherein the processor iscapable of processing data instructions stored in the computer readablestorage media. The host device also includes a USB port 134 thatreceives and connects with a plug at the other end of the USB cable 104.

FIG. 2 is a schematic block diagram illustrating another example of theUSB communication system 100 shown in FIG. 1.

Similar to the example shown in FIG. 1, this example shown in FIG. 2also includes the dockable instrument assembly 102, the USB cable 104,and the host device 106. The dockable instrument assembly 102 includesthe portable instrument 110 and the docking station 112. The portableinstrument 110 includes the instrument 120 and the cradle 122, thoughsome portable instruments 110 do not include a cradle 122.

More specifically, the example shown in FIG. 2 illustrates a divided USBcommunication device in which a first portion 152 of the USBcommunication device is part of the portable instrument 110, while asecond portion 154 of the USB communication device is part of thedocking station 112.

FIG. 2 also illustrates additional example components of the USBcommunication system 100. For example, the portable instrument 110includes instrument electronics 162 and power source 164, and the firstportion 152 of the USB communication device includes a processing device166 and a serial communication device 168. The docking station 112includes charging circuitry 172 and a power supply 174, and the secondportion 154 of the USB communication device includes a serial to USBconverter 176, which itself includes a processing device 178.

Before discussing the USB communication device in further detail, theother example components of the portable instrument 110, docking station112, and host device 106 are discussed below.

The portable instrument 110 (including the instrument 120) operates toperform a desired function, and includes instrument electronics 162 thatperform that function. For example, in some embodiments the instrument120 is a thermometer. In this example, the instrument electronics 162operate to determine a temperature of a patient. When the thermometer isan infrared thermometer, for example, the instrument electronics 162include an infrared emitter and detector, and electronics suitable fordetermining a temperature of the patient from detected infrared signals.A wide variety of other instruments can be utilized in otherembodiments. The instrument electronics 162 typically include some typeof processing device and a computer readable storage device that storesprogram instructions, which can be processed by the processing device toperform the appropriate operations defined by the program instructions.Further, many embodiments include at least some type of sensor, whichoperates to detect a property, characteristic, or event, and generatedata associated with the sensor. In typical embodiments, the instrument110 operates to generate data for transmission to the host device 106,and such data is transmitted utilizing the divided USB communicationdevice described herein.

The power source 164 stores energy to power the electronic components ofthe portable instrument 110 when the portable instrument 110 is turnedon and disconnected from the docking station. An example of a powersource 164 is a battery. Another example of a power source is a supercapacitor. Multiple power sources or combinations of power sources areincluded in yet other embodiments.

In some embodiments the portable instrument 110 is associated with acradle 122. For example, in some embodiments the instrument 120 housedin the cradle 122 when it is not in use. The cradle 122 can also storeaccessories or other components used with the portable instrument 110.In some embodiments, the cradle 122 includes electrical contacts andelectrical conductors to transfer signals between the instrument 120 andthe docking station 112 when the portable instrument 110 is insertedinto the docking station. The cradle 122 can also include one or moreelectronic components, such as a pull-down resistor electricallyconnected with two or more of the electrical conductors, as described inmore detail herein. In other possible embodiments, the cradle 122includes no electronic components, other than contacts and conductors.

In some embodiments, the portable instrument 110 does not include acradle 122. For example, the instrument 120 can be inserted directlyinto the docking station 112 where direct electrical contact is madebetween the instrument 120 and the docking station 112. In someembodiments the charging circuitry 172 detects a charge status of thepower source 164 and provides power according to the detected chargestatus. For example, if the power source 164 is not fully charged, thecharging circuitry 172 can operate in a fast charging mode, while thecharging circuitry 172 operates in a trickle charge mode when the powersource 164 is detected to be fully charged.

In some embodiments, the docking station 112 includes charging circuitry172 that operates to recharge the power source 164 when the portableinstrument 110 is inserted into the docking station 112. The chargingcircuitry 172 is powered by a power source, such as the power supply174. In some embodiments, the power supply 174 is a battery or a supercapacitor. In other embodiments, the power supply 174 receives powerfrom an external power source, such as mains power, and operates toconvert the received power into a form suitable for delivery to thecharging circuitry 172 and other electronic components of the dockingstation 112.

The host device 106 includes a USB communication device 182 thatcommunicates with the divided USB communication device of the dockableinstrument assembly 102, such as to receive data generated by theinstrument electronics 162.

The host device 106 also includes host device electronics 184 thatoperate to perform the desired functions of the host device 106. Forexample, when the host device 106 is a vital signs monitor, the hostdevice electronics 184 operate to monitor vital signs. An example of ahost device 106 is illustrated and described in more detail herein withreference to FIG. 6.

Turning now to the divided USB communication device of the dockableinstrument assembly 102, the divided USB communication device includesthe first portion 152 and the second portion 154. The first portion 152is included in the portable instrument 110, while the second portion 154is included in the docking station 112. In some embodiments, the firstportion 152 and the second portion 154 collectively operate tocommunicate with the host device 106 according to a USB communicationprotocol, but are separately unable to communicate with the host device106 according to the USB communication protocol.

In this example, the first portion 152 includes a processing device 166and a serial communication device 168. The processing device 166 is adevice capable of processing data instructions, such as amicroprocessor. Various other processing devices may also be usedincluding central processing units (“CPUs), microcontrollers,programmable logic devices, field programmable gate arrays, digitalsignal processing (“DSP”) devices, and the like. Processing devices maybe of any general variety such as reduced instruction set computing(RISC) devices, complex instruction set computing devices (“CISC”), orspecially designed processing devices such as an application-specificintegrated circuit (“ASIC”) device, for example. In some embodiments,the processing device 166 is shared with the instrument electronics 162.

In some embodiments, the processing device is programmed to send andreceive messages in a manner corresponding to the USB communicationprotocol. The processing device 166 is communicatively coupled to (orpart of) the instrument electronics 162 to receive or generate data tobe transmitted to the host device 106 from the instrument electronics.

The serial communication device 168 is communicatively coupled to theprocessing device 166, and operates to communicate data serially betweenthe portable instrument 110 and the docking station 112. Examples ofserial communication devices 168 are communication devices thatcommunicate data according to one of the RS-232, RS-485, and RS-422 datacommunication standards using a serial data communication format. Otherembodiments include other serial communication devices, which canoperate according to other serial data communication standards, or canutilize a proprietary serial communication protocol. Some embodimentsutilize a serial communication device 168 that communicates data acrossa single electrical conductor, while in other embodiments communicationoccurs across multiple conductors, such as utilizing differentialsignaling. Power and ground conductors are also commonly providedbetween the serial communication device 168 and the second portion 154.

In some embodiments, the serial communication device 168 and theprocessing device 166 are a single device, or components of a singlesystem.

An advantage of utilizing a serial communication device 168 in theportable instrument 110 is that the serial communication device 168 istypically less expensive than a USB communication device. Serialcommunication is less complex than USB communication, and therefore thecomplexity of the portable instrument 110 is also reduced by utilizingserial communication device 168. Additionally, serial communication isless constrained to particular connectors than USB communication, and awide variety of possible serial connectors can therefore be used. Forexample, some suitable connectors have lower cost then a typical USBconnector.

In typical embodiments, the host device 106 is incapable ofcommunicating directly with the serial communication device 168 (andvice versa), at least through the USB port 134, because suchcommunication is in a non-USB format according to a non-USB datacommunication protocol. However, the content of messages from the hostportable instrument 110 does conform to the USB communication protocol,except for the format in which the messages are transmitted. Similarly,in some embodiments, communications from the host device 106 (and USBcommunication device 182) that are transmitted through the USB port 134are not in the serial data communication format according to a serialdata communication protocol.

Accordingly, the second portion 154 of the USB communication device 182is provided, which when coupled with the first portion 152, allows theportable instrument 110 to communicate with the host device 106.

In this example, the second portion 154 includes a serial to USBconverter 176. The serial to USB converter 176 operates to convertelectrical signals associated with a serial communication (such as fromthe serial communication device 168) to electrical signals associatedwith USB communication (such as for delivery to the USB communicationdevice 182). Additionally, the serial to USB converter 176 also operatesin the reverse manner, to convert electrical signals associated with USBcommunication (such as from the USB communication device 182) toelectrical signals associated with serial communication.

In some embodiments, the serial to USB converter 176 is or includes aprocessing device 178. One example of a suitable serial to USB converter176 is Part No. C8051F327 USB mixed-signal microcontroller availablefrom Silicon Laboratories Inc. of Austin, Tex., along with associatedelectronics. The mixed-signal microcontroller includes a USB controllerfor communicating with the USB communication device 182, as well as aUART serial port for communicating with the serial communication device168.

FIG. 3 is a schematic block diagram illustrating another example of thefirst portion 152 of the divided USB communication device, and thecradle 122. The first portion 152 includes the processing device 166 andthe serial communication device 168. In this example, the first portion152 also includes electronic components such as a buffer 190, inverters192 and 194, and a resistor R1. Electrical connections are made to thecradle 122 and/or the docking station 112 through pins, including thecharge pin 202, /TXD pin 204, /RXD pin 206, and ground pin 208. Thecradle 122 includes electrical conductors and a resistor R2, andincludes pins corresponding to pins 202, 204, 206, and 208 of the firstportion 152. In other possible embodiments, the resistor R2 can beincluded in the first portion 152, or elsewhere in the instrument 120(shown in FIG. 2).

In some embodiments, the divided USB communication device is designed toconform with one or more design criteria, as follows. First, the firstportion 152 should be able to determine when it is inserted or withdrawnfrom the docking station 112 (shown in FIGS. 2 and 4). Second, thedocking station 112 should be able to determine when the portableinstrument 110 is in the docking station 112 and when it has beenremoved. Third, the docking station 112 should not cause USB enumerationto occur at the host device 106 when the portable instrument 110 is notin the docking station 112. Fourth, the externally accessible pins ofthe portable instrument 110 should have no voltage present (comparedwith the portable instrument 110 ground) when the portable instrument110 is not in the docking station 112. Some embodiments confirm with allfour design criteria, while other embodiments conform to less than allof the design criteria. Yet other embodiments confirm with none of thefour design criteria, or a different set of one or more design criteria.

The charge pin 202 is electrically connected to the power source 164 andreceives power from the docking station 112 to recharge power source164. In some embodiments, the power from the power source 164 is alsoused to power the processing device 166 and serial communication device168 through buffer 190.

The /TXD pin 204 is electrically coupled to the TXD pin of theprocessing device 166 and serial communication device 168 through theinverter 192.

The /RXD pin 206 is electrically coupled to the RXD pin of theprocessing device 166 and serial communication device 168 through theinverter 194 and also to the ENABLE pin through the resistor R1. Inanother possible embodiment, the resistor R1 can be coupled to VIN (oranother source of a logic high). In either case, the resistor R1 is apull-up resistor that acts to maintain the RXD pin at a logic high inthe absence of a signal or coupling of the pull down resistor R2.However, by coupling the resistor R1 to the ENABLE pin, the processingdevice 166 can supply the logic high to the ENABLE pin only whenperforming a check for the docking station 112. This prevents excessleakage current that would continually be flowing through the resistorR1 if R1 is connected to a constant logic high source. In other words,power is saved by connecting the resistor R1 to the ENABLE pin, andselectively setting the ENABLE pin to a logic high only when checkingthe RXD pin to determine if the portable instrument 110 has beenconnected with the docking station 112.

The /RXD pin 206 is electrically coupled with the RXD pin throughinverter 194, and with the ENABLE pin through resistor R1. Because the/RXD pin 206 is electrically coupled to the RXD and ENABLE pins throughinverter 194, the pull-up resistor R1, which operates to pull the RXDpin to a logic high, also operates to pull the/RXD pin 206 to a logiclow in the absence of a signal from the docking station 112.

The /RXD pin 206 is also electrically coupled to the resistor R2, atleast when the instrument 110 is in the cradle 122. In some embodimentsthe resistance of R2 is much less than the resistance of R1, such as afactor of 10 times less. As one example, the resistor R1 has aresistance of 100K Ohms, and the resistor R2 has a resistance of 10KOhms. Other embodiments have other resistances.

The ground pin 208 is electrically coupled to the ground of the portableinstrument 110, such as from the power source 164.

As shown, the cradle 122 is configured as a pass-through device, to passthe electrical signals on the pins 202, 204, 206, and 208 to the dockingstation 112 (when connected to the docking station 112), and vice versa.

The first portion 152 communicates between the instrument electronics162 and the second portion 154. For example, the first portion 152 iscoupled to the instrument electronics 162 to receive data from theinstrument electronics 162 to be transferred to the host device 106. Theprocessing device 166 and serial communication device 168 convert thedata into a serial data communication format, and transmit the data tothe second portion in the serial format. For example, the data istransmitted to the second portion 154 across the TXD and /TXD pin 204 insome embodiments.

FIG. 4 is a schematic block diagram of an example of the second portion154 of the divided USB communication device. In this example, the secondportion 154 includes the serial to USB converter 176. Additionalelectronic components are included in some embodiments, such as apull-up resistor R3 and inverters 212 and 214. The second portion 154connects with the first portion 152 (or cradle 122) through charge pin222, /RXD pin 224, /TXD pin 226, and ground pin 228. The second portion154 connects with the host device 106 (and USB cable 104) through the D+pin 232 and D− pin 234. Additional pins (such as power and ground pins)are included in some embodiments. Yet other embodiments have fewer ordifferent pins.

The charge pin 222 connects with the charging circuitry 172 to providepower for recharging the power source 164 of the portable instrument110, when the portable instrument 110 is connected with the dockingstation 112. The charging circuitry 172 receives power from the powersupply 174. In another possible embodiment, the charging circuitry 172receives power from the USB communication device 182 (through USB cable104).

The /RXD pin 224 is electrically coupled to a voltage source (VCC)through pull-up resistor R3, and to the RXD pin of the serial to USBconverter 176 through inverter 212.

The /TXD pin 226 is electrically coupled to the TXD pin of the serial toUSB converter through the inverter 214.

The ground pin 228 is electrically coupled to the electrical ground ofthe docking station 112.

The second portion 154 communicates between the first portion 152 andthe host device 106. For example, data is received in a serialcommunication format from the first portion 152 through the /RXD pin 224and the RXD pin. The data is then converted into a USB communicationformat, and transmitted to the host device through the D+ pin 232 andthe D− pin 234 and through the USB cable 104 electrically coupled to thepins 232 and 234. In some embodiments, data is also received from thehost device through the D+ pin 232 and the D− pin 234 (and USB cable104) in the USB communication format, which is then converted into theserial communication format by the serial to USB converter 176, andtransmitted through the TXD pin and /TXD pin 226 to the first portion152.

In some embodiments, the docking station 112 detects when the portableinstrument 110 is connected to the docking station 112. In one example,the docking station 112 monitors the RXD pin for a transition thatoccurs within a predetermined time period (e.g., 40 ms). When thetransition is detected, the docking station 112 determines that theportable instrument 110 has been placed into the docking station 112. Atthis time, the docking station 112 initializes the USB interface causinga USB arrival. The host device 106 detects and recognizes the connectionof the portable instrument 110. Even though the docking station 112 wasalready connected to the host device 106 through the USB cable 104, theUSB arrival does not occur until the portable instrument 110 is placedinto the docking station. This prevents the host device 106 fromattempting to communicate with the docking station 112, for example,before the portable instrument 110 is connected and available to receivethe communication.

In some embodiments, the docking station 112 monitors the RXD pin todetermine when the portable instrument 110 is removed from the dockingstation 112. In one example, the portable instrument 110 is determinedto be removed from the docking station 112 if the RXD pin remains at alogic high for greater than a predetermined time period (e.g., 40 ms).When this occurs, the second portion 154 determines that the portableinstrument 110 has been removed, and resets itself. This causes the hostdevice 106 to recognize a USB device departure, and to de-enumerate. Inother words, the host device 106 also acts as though the dockableinstrument assembly 102 has been disconnected from the USB port 134(shown in FIG. 1), even though the docking station 112 remains connectedto the USB port 134 through the USB cable 104.

FIG. 5 is a schematic diagram illustrating an example implementation ofthe second portion 154 of the divided USB communication device, such ascan be incorporated into the docking station 112.

In this example, the second portion 154 includes the serial to USBconverter 176 and associated electronic components, including electricalconductors and connection points. The connection points include the /RXDpin 224, /TXD pin 226, D+ pin 232, and D− pin 234. Other electroniccomponents include resistors R3, R7, R18, R35, and R36, electrostaticdischarge (ESD) suppressors D11 and D12, 4 pin programming adapter J2,avalanche diodes D1, capacitors C3 and C4, and transformer FL1. Anexample of the electrical connections between the USB converter 176 andthe various electronic components are illustrated in FIG. 5.

The example implementation shown in FIG. 5 operates in the same manneras the example illustrated in and described with reference to FIG. 4.For example, serial communications between the serial to USB converter176 and the first portion 152 (shown in FIG. 3) occur through the /RXDpin 224 and the /TXD pin 226. USB communications occur between theserial to USB converter 176 and the host device 106 through the D+ andD− pins 232 and 234.

In this example, the serial to USB converter 176 is the Part No.C8051F327 USB mixed-signal microcontroller. Other embodiments utilizeother serial to USB communication devices.

One example of a suitable ESD suppressor (D11 and D12) is the Part No.PGB1010603MR available from Littelfuse, Inc. of Chicago, Ill.

One example of a suitable avalanche diode (D1) package is the Part No.SP0503BAHT Transient Voltage Suppression Avalanche Diode Array,available from Littelfuse, Inc.

The resistors are selected to have resistances and tolerancesappropriate for the given implementation. In one example, the resistorR3 is a 3.3K Ohm resistor, the resistor R18 is a 10K Ohm resistor, andthe resistors R35 and R36 are 22 Ohm resistors.

The capacitors are also selected to have characteristics appropriate forthe given implementation. In one example, the capacitors C3 and C4 are a1 μF capacitor and a 0.1 μF capacitor, respectively.

The transformer FL1 is coupled to the D+ and D− pins 232 and 234, insome embodiments, which is used for isolation to protect the dockingstation 112 electronics from any large voltages or voltage spikes thatmay be received at the USB port 132.

The charge_on and charge_done pins are used in some embodiments by thecharging circuitry 172 to determine when to charge the power source 164of the portable instrument 110.

FIG. 6 is a schematic block diagram of an example host device 106.

The host device 106 includes, in some embodiments, at least oneprocessing device 240, such as a central processing unit (CPU). Avariety of processing devices are available from a variety ofmanufacturers, for example, Intel or Advanced Micro Devices. In thisexample, the host device 106 also includes a system memory 242, and asystem bus 244 that couples various system components including thesystem memory 242 to the processing device 240. The system bus 244 isone of any number of types of bus structures including a memory bus, ormemory controller; a peripheral bus; and a local bus using any of avariety of bus architectures.

Examples of devices suitable for the host device 106 include a vitalsigns monitor, a desktop computer, a laptop computer, a tablet computer,a mobile computing device (such as a smart phone, an iPod® or iPad®mobile digital device, or other mobile devices), or other devicesconfigured to process digital instructions and communicate through a USBcommunication device 182.

The system memory 242 includes read only memory 246 and random accessmemory 248. A basic input/output system 250 containing the basicroutines that act to transfer information within host device 106, suchas during start up, is typically stored in the read only memory 246.

The host device 106 also includes a secondary storage device 252 in someembodiments, such as a hard disk drive, for storing digital data. Thesecondary storage device 252 is connected to the system bus 244 by asecondary storage interface 254. The secondary storage devices 252 andtheir associated computer readable media provide nonvolatile storage ofcomputer readable instructions (including application programs andprogram modules), data structures, and other data for the host device106.

Although the exemplary environment described herein employs a hard diskdrive as a secondary storage device, other types of computer readablestorage media are used in other embodiments. Examples of these othertypes of computer readable storage media include magnetic cassettes,flash memory cards, digital video disks, Bernoulli cartridges, compactdisc read only memories, digital versatile disk read only memories,random access memories, or read only memories. Some embodiments includenon-transitory media. Additionally, such computer readable storage mediacan include local storage or cloud-based storage.

A number of program modules can be stored in secondary storage device252 or memory 242, including an operating system 256, one or moreapplication programs 258, other program modules 260 (such as thesoftware engines described herein), and program data 262. The hostdevice 106 can utilize any suitable operating system, such as MicrosoftWindows™, Google Chrome™, Apple OS, and any other operating systemsuitable for a host device.

In some embodiments, a user provides inputs to the host device 106through one or more input devices 264. Examples of input devices 264include a keyboard 266, mouse 268, microphone 270, and touch sensor 272(such as a touchpad or touch sensitive display). Other embodimentsinclude other input devices 264. The input devices are often connectedto the processing device 240 through an input/output interface 274 thatis coupled to the system bus 244. These input devices 264 can beconnected by any number of input/output interfaces, such as a parallelport, serial port, game port, or a universal serial bus interface (suchas available through the USB port 134 and USB communication device 182).Wireless communication between input devices and the interface 274 ispossible as well, and includes infrared, BLUETOOTH® wireless technology,802.11a/b/g/n, cellular, or other radio frequency communication systemsin some possible embodiments.

In this example embodiment, a display device 276, such as a monitor,liquid crystal display device, projector, or touch sensitive displaydevice, is also connected to the system bus 244 via an interface, suchas a video adapter 278. In addition to the display device 276, the hostdevice 106 can include various other peripheral devices (not shown),such as speakers or a printer.

When used in a local area networking environment or a wide areanetworking environment (such as the Internet), the host device 106 istypically connected to a data communication network through a networkinterface 280, such as an Ethernet interface. In another possibleembodiment, the host device 106 communicates through a wireless networkinterface, such as utilizing WIFI, BLUETOOTH, cellular, or otherwireless data communication protocols. Other possible embodiments useother communication devices. For example, some embodiments of the hostdevice 106 include a modem.

The host device 106 typically includes at least some form of computerreadable media. Computer readable media includes any available mediathat can be accessed by the host device 106. By way of example, computerreadable media include computer readable storage media and computerreadable communication media.

Computer readable storage media includes volatile and nonvolatile,removable and non-removable media implemented in any device configuredto store information such as computer readable instructions, datastructures, program modules or other data. Computer readable storagemedia includes, but is not limited to, random access memory, read onlymemory, electrically erasable programmable read only memory, flashmemory or other memory technology, compact disc read only memory,digital versatile disks or other optical storage, magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devices,or any other medium that can be used to store the desired informationand that can be accessed by the host device 106. Computer readablestorage media does not include computer readable communication media.

Computer readable communication media typically embodies computerreadable instructions, data structures, program modules or other data ina modulated data signal such as a carrier wave or other transportmechanism and includes any information delivery media. The term“modulated data signal” refers to a signal that has one or more of itscharacteristics set or changed in such a manner as to encode informationin the signal. By way of example, computer readable communication mediaincludes wired media such as a wired network or direct-wired connection,and wireless media such as acoustic, radio frequency, infrared, andother wireless media. Combinations of any of the above are also includedwithin the scope of computer readable media.

The host device illustrated in FIG. 6 is also an example of programmableelectronics, which may include one or more such host devices 106, andwhen multiple host devices 106 are included, such host devices can becoupled together with a suitable data communication network so as tocollectively perform the various functions, methods, or operationsdisclosed herein.

FIG. 7 is a flow chart illustrating an example method 290 ofcommunicating with a USB-enabled host device. In this example, themethod includes operations 292, 294, and 296.

The operation 292 is performed to monitor for the insertion of aportable instrument into the docking station 112. The operation 292continues until the insertion of the portable instrument into thedocking station is detected.

After operation 292, the operation 294 is performed to initiatecommunication with the host device 106. In some embodiments, theinitiation of communication alerts the host device to an arrival of theportable instrument, and causes enumeration of the portable instrument110 by the host device 106.

The operation 296 is performed to facilitate communication between theportable instrument 110 and the host device 106. An example of operation296 is illustrated in FIG. 8.

FIG. 8 is a flow chart illustrating an example method of facilitatingcommunication between the portable instrument 110 and a host device 106.FIG. 8 also illustrates an example of operation 296, shown in FIG. 7. Inthis example, the method includes operations 302, 304, and 306. In someembodiments, the method and operations are performed by the dockingstation 112.

The operation 302 is performed to receive data from the portableinstrument 110 in a non-USB format.

The operation 304 is performed to convert the data into a USB format.

The operation 306 is performed to transmit the data to the host device106 in the USB format.

In some embodiments, data communication also occurs from the host device106 to the portable instrument 110. For example, data is received fromthe host device in a USB format. The data is converted into a non-USBformat, such as a serial data communication format. The data is thentransmitted to the portable instrument in the non-USB format.

FIG. 9 is a flow chart illustrating a method 310 of terminatingcommunication with a USB-enabled host device. In this example, themethod includes operations 312 and 314.

The operation 312 is performed to monitor for the disconnection andremoval of the portable instrument from the docking station 112.Monitoring continues until the disconnection is detected.

The operation 314 is then performed to terminate communication with thehost device. In some embodiments, the termination of communicationalerts the host device to the departure of the portable instrument, andcauses de-enumeration of the portable instrument 110 at the host device106.

The various embodiments described above are provided by way ofillustration only and should not be construed to limit the claimsattached hereto. Those skilled in the art will readily recognize variousmodifications and changes that may be made without following the exampleembodiments and applications illustrated and described herein, andwithout departing from the true spirit and scope of the followingclaims.

What is claimed is:
 1. A docking station comprising: a housing having areceptacle formed therein, the receptacle sized and configured toreceive and support at least a portion of a portable medical instrumentand including electrical contacts arranged to electrically connect withthe portable medical instrument, wherein the portable medical instrumentincludes a first portion of a USB communication device adapted tocommunicate in a serial data communication format; and a second portionof the USB communication device enclosed in the housing, the secondportion comprising: a serial to USB converter arranged in the housingand electrically connected to the electrical contacts, wherein theserial to USB converter is arranged and configured to convert betweenthe serial data communication format and a USB data communication formatto facilitate communication between the portable medical instrument anda host device; and electronic circuitry that detects the electricalconnection of the portable medical instrument with the electricalcontacts and initiates the communication with the host device afterdetecting the electrical connection, which causes enumeration of theportable medical instrument at the host device.
 2. The docking stationof claim 1, wherein the electronic circuitry further detects theelectrical disconnection of the portable medical instrument from theelectrical contacts by detecting an absence of a logic signal andterminates the communication with the host device after detecting theelectrical disconnection.
 3. The docking station of claim 2, wherein thetermination of the communication causes de-enumeration of the portablemedical instrument at the host device.
 4. The docking station of claim1, wherein the serial to USB converter is part of the electroniccircuitry.
 5. A portable medical instrument and cradle combinationcomprising: an instrument including: instrument electronics adapted togenerate data associated with a physiological characteristic of anindividual; and a first portion of a USB communication device, the firstportion comprising: a processing device, the processing deviceprogrammed to send and receive messages including the data; and a serialcommunication device that receives the messages from the processingdevice and transmits the messages to a docking station in a non-USBserial data communication format; and a cradle having a receptacle sizedto receive at least a portion of the cradle therein, and electricallyconnected to the instrument when the instrument is in the receptacle,wherein the cradle includes electrical conductors for passing electricalsignals from the instrument to the docking station, wherein the portableinstrument generates no voltage at the electrical conductors when theinstrument and cradle are separated from the docking station.
 6. Theportable medical instrument and cradle combination of claim 5, whereinthe first portion further includes electrical contacts, wherein thefirst portion determines that the portable instrument is connected tothe docking station by detecting a logic level transition that occursupon electrical connection of the portable instrument to the dockingstation.
 7. The portable medical instrument and cradle combination ofclaim 5, wherein the non-USB serial data communication format conformsto one of the following serial data communication standards: RS-232,RS-485, and RS-422.
 8. The portable medical instrument and cradlecombination of claim 5, wherein the portable medical instrument isincapable of direct communication with a USB communication device of ahost device through a USB cable.
 9. The portable medical instrument andcradle combination of claim 5, wherein the portable medical instrumentis an infrared ear thermometer.
 10. The portable medical instrument andcradle combination of claim 5, wherein the cradle further comprises atleast one pull-down resistor electrically coupled between at least twoof the electrical conductors, wherein the instrument detects when it isinserted into the cradle by detecting a voltage change caused at leastin part by the electrical coupling between the electrical conductorsthrough the pull-down resistor.
 11. A dockable instrument assemblyincluding a divided universal serial bus (USB) communication deviceconfigured to communicate with a USB-enabled host device, the dockableinstrument assembly comprising: a portable instrument comprising:instrument electronics operable to generate data to be communicated tothe host device, the data being associated with a physiologicalcharacteristic of an individual; and a first portion of the divided USBcommunication device comprising a serial communication device, whereinthe first portion is arranged and configured to receive the data fromthe instrument electronics and transmit the data in a serial format withthe serial communication device; and a docking station comprising: areceptacle sized to receive at least a portion of the portableinstrument therein; a second portion of the divided USB communicationdevice, the second portion comprising a serial to USB converter arrangedand configured to: detect when the portable instrument is inserted intothe receptacle; after detecting insertion of the portable instrumentinto the receptacle, initiate communication with the host device whichcauses enumeration of the portable instrument at the host device; andfacilitate communication between the portable instrument and the hostdevice.
 12. The dockable instrument assembly of claim 11, wherein tofacilitate the communication between the portable instrument and thehost device, the serial to USB converter is further arranged andconfigured to: receive the data from the portable instrument in theserial format; convert the data into a USB format; and transmit the datato the host device in the USB format.
 13. A method of communicating witha USB-enabled host device, the method comprising: monitoring forinsertion of a portable medical instrument into a docking station;detecting the insertion of the portable medical instrument into thedocking station, the portable medical instrument configured tocommunicate with the docking station through a non-USB datacommunication device in a non-USB format; after detecting the insertionof the portable medical instrument, initiating communication with thehost device to alert the host device to an arrival of the portablemedical instrument and cause enumeration of the portable medicalinstrument at the host device; and facilitating communication betweenthe portable medical instrument and the host device.
 14. The method ofclaim 13, wherein facilitating communication between the portablemedical instrument and the host device further comprises: receiving datafrom the non-USB data communication device of the portable medicalinstrument in the non-USB format; converting the data into a USB format;and transmitting the data to the host device in the USB format.
 15. Themethod of claim 14, wherein transmitting the data to the host device inthe USB format occurs through a USB cable.
 16. The method of claim 15,wherein the non-USB data communication device is a serial communicationdevice.
 17. The method of claim 13, wherein while monitoring for theinsertion of the portable medical instrument, the docking station doesnot trigger device enumeration at the host device.
 18. A docking stationcomprising: a housing having a receptacle formed therein, the receptaclesized and configured to receive and support at least a portion of aportable medical instrument and including electrical contacts arrangedto electrically connect with the portable medical instrument, whereinthe portable medical instrument includes a first portion of a USBcommunication device adapted to communicate in a serial datacommunication format; and a second portion of the USB communicationdevice enclosed in the housing, the second portion comprising: a serialto USB converter arranged in the housing and electrically connected tothe electrical contacts, wherein the serial to USB converter is arrangedand configured to convert between the serial data communication formatand a USB data communication format to facilitate communication betweenthe portable medical instrument and a host device; and electroniccircuitry that detects the electrical connection of the portable medicalinstrument with the electrical contacts and initiates the communicationwith the host device after detecting the electrical connection, andwherein the electronic circuitry further detects the electricaldisconnection of the portable medical instrument from the electricalcontacts by detecting an absence of a logic signal and terminates thecommunication with the host device after detecting the electricaldisconnection.